This invention describes a set of machines, and a structural system capable of building structures by the additive assembly of discrete parts. These digital material assemblies (described, in part, in U.S. Pat. No. 7,848,838, US20120094060, WO2014025944, US20140302261, US20140300211) constrain the constituent parts to a discrete set of possible positions and orientations. In doing so, the structures exhibit many of the properties inherent in digital communication such as error correction, fault tolerance and allow the assembly of precise structures with comparatively imprecise tools. The machines responsible for assembling digital materials should leverage, to the extent possible, the interlocking and error-correction naturally present in the discrete parts.
Field of Technology
Prior work has been done in making machines that assemble structures from discrete parts. Hiller et al. showed a method of parallel part placement of voxel spheres in [J. Hiller and H. Lipson, “Methods of Parallel Voxel Manipulation for 3D Digital Printing,” in Proceedings of the 18th solid freeform fabrication symposium., 2007, p. 12.]. These voxels, however, do not interlock in a structural way and so a binder must be used after depositing the spheres. Customizable pultrusion systems have been used for creating high performance iso-grid tubes [D. Darooka and D. Jensen, “Advanced Space structure Concepts and their development”, in AIAA Structures, Structural Dynamics, and Materials Conference, 2001.]. Deployable composite structures have been used in space applications for decades, and their reliability and stiffness to weight ratio are optimized [T. Murphey, “‘Booms and Trusses,’” in Recent Advances in Gossamer Spacecraft, 2006, p. 1-43.]. Few of these processes are reversible, incremental, or able to result in volumetric structures. 3D printing of lattices results in ultralight, high performance structures [X. Zheng, et al, “Ultralight, ultrastiff mechanical metamaterials.,” Science, vol. 344, no. 6190, pp. 1373-7, 2014.], but is not scalable beyond the printing machine. Assembled cellular lattices have been used as sandwich materials [H. Wadley, et al, “Fabrication and Structural Performance of Periodic Cellular Metal Sandwich Structures”, Composites Science and Technology, 63, p. 2331-2343, 2003.] and space filling structures [K. Cheung and N. Gershenfeld, “Reversibly assembled cellular composite materials.,” Science, vol. 341, no. 6151, pp. 1219-21, 2013.], but their assembly is manual and thus throughput and scale limited.